Field experiment to restore a gravel bar and control growth of trees in the Asahi River

Shiro Maeno, Satoshi Watanabe

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

The number of active gravel bars on the Asahi River in Okayama Prefecture (located in western Japan) has continuously decreased over the last 20 years, whereas stable vegetated areas have rapidly expanded on river bars during the same period. In a basic study to examine the re-establishment of gravel bars as a river restoration technique, an artificial gravel bar was experimentally created in the field. The effect of flood flows on the bar was then examined. Preliminary numerical simulations of the annual scale flood predicted that flooding strong enough to move stones would uniformly flow over the restored gravel bar and that the gravel bed could be maintained due to the increase of shear stress on the bed. However, monitoring of the restored bar showed that branches of Salicaceous species (willows) and seeds of Eragrostis curvula (weeping love-grass) quickly re-vegetated the downstream part of the test area. Additional numerical simulations, using the observed hydrograph, suggested that branches and seeds would be brought to the bar during the flood recession period.

Original languageEnglish
Pages (from-to)225-232
Number of pages8
JournalInternational Journal of River Basin Management
Volume6
Issue number3
Publication statusPublished - 2008

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gravel
river
seed
field experiment
hydrograph
shear stress
simulation
flooding
grass
monitoring

Keywords

  • Control growth of trees
  • Field experiment
  • Gravel bar
  • River restoration
  • The Asahi River

ASJC Scopus subject areas

  • Water Science and Technology

Cite this

Field experiment to restore a gravel bar and control growth of trees in the Asahi River. / Maeno, Shiro; Watanabe, Satoshi.

In: International Journal of River Basin Management, Vol. 6, No. 3, 2008, p. 225-232.

Research output: Contribution to journalArticle

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